Conventional tillage implements such as the disk harrow, disk cultivator and rotating hoe are not completely suitable for preparing ground for seeding where legumes are to be grown in established grass sod.
In order to provide a tillage apparatus better suited for preparing ground for seeding or grassland renovation where sod is present, towed implements having a series of cutting wheels driven to open a furrow have been developed. Devices of this type are shown, for example, in U.S. Pat. Nos. 4,023,510; 4,043,281; 4,043,404; and 4,051,792. . This type of tillage implement is particularly useful where legumes are to be grown in established grass sod, especially since the ground surface is often uneven or rocky and may have grass swards of differing thicknesses thereon. The implement is also useful for interseeding grasses such as rye and wheat into Bermuda grass.
Cutting of the sward and sod mat and provision of a furrow therein has been a continuing problem. Although cutter wheels for the tillage implements have been known and suggested, such wheels have not been completely satisfactory. Wearing of the cutter wheels is a common problem because the wheels are driven in the soil. Additionally the rough, rocky terrain often encountered adds to the problem of wear and breakage.